Compress Words

#include<bits/stdc++.h>
using namespace std;
const int N = 1e6 + 10;
int ne[N];
void kmp(string ss) {
	int n = ss.length();
	ss = ' ' + ss;
	ne[0] = ne[1] = 0;
	for (int i = 2,j=0; i <= n; i++) {
		while (j && ss[i] != ss[j + 1]) j = ne[j];
		if (ss[i] == ss[j + 1]) j++;
		ne[i] = j;
	}
}
int main() {
	int n;
	cin >> n;
	string ans, s;
	cin >> ans;
	n--;
	while (n--) {
		cin >> s;
		int len = min(s.length(), ans.length());
		string ss = s + "#$" + ans.substr(ans.length()-len,len);
		kmp(ss);
		for (int i = ne[ss.length()]; i < s.length(); i++) ans+=s[i];

	}
	cout << ans;
	return 0;
}